1. Field of the Invention
The present invention relates to an apparatus for inserting into a larynx of a patient a laryngeal mask which is used in general anesthesia, intensive care, critical care or the like to maintain an airway.
2. Description of Related Art
As a method of maintaining an oral airway in an anesthetic management or the like, there has conventionally been used a method of endotracheal intubation by using a laryngoscope. Recently, as shown in FIG. 1A, there is also known a method of using a laryngeal mask 1 which may simply be inserted into the larynx.
The laryngeal mask 1 is made up of an oval mask body 2 and a hollow cuff 3 which is provided on the periphery of the mask body 2. A respiratory tube 4 is connected to a connecting portion 4a on the outside surface (i.e., the wrong side as opposed to the right side) of the mask. The respiration is performed through the holes 2a which are formed in the mask body 2. A tube 5 for injecting air into the cuff 3 is connected to the cuff 3. In a condition in which the cuff 3 is deflated by extracting air therefrom, the laryngeal mask 1 is inserted into the larynx of a patient. Then, the cuff 3 is inflated by injecting air thereinto. In this manner, an airway is maintained by covering the larynx with the mask 1 as shown in FIG. 1B.
In inserting the laryngeal mask 1 into the larynx, it is normal practice to bend the head of the patient backwards, push the laryngeal mask along his palatine wall to prevent the mask from twisting, and urge the laryngeal mask 1. In order to do so it is necessary to insert fingers of an operator into the patient's oral cavity, resulting in a fear of infection. In addition, for the purpose of preventing infection, it is recommended to use rubber gloves. However, according to the report by the FDA (Food and Drug Administration) of the U.S.A. in July, 1991, the occurrence of allergy through the use of rubber gloves has become a problem. Further, as shown in FIG. 1C, the Duff 3 in the front (i.e., head) end portion of the mask 1 will sometimes be peeled off towards the outside thereof, with the result that the mask 1 can no longer be inserted into the larynx.
Considering the above disadvantages, the present invention has an object of providing an apparatus which can surely insert a laryngeal mask into the larynx without the necessity of inserting the operator's fingers into the patient's oral cavity.
According to the first aspect of the present invention, there is provided an apparatus for inserting a laryngeal mask comprising: a holder portion; a pair of clamp bars which extend forwards from the holder portion and which are adapted to hold therebetween in a pinching manner a tube connecting portion provided on an outside surface of the laryngeal mask, the pair of clamp bars being connected together at their front ends to thereby form an abutment portion which is adapted to abut a front end of the outside surface of the laryngeal mask; and a band piece which extends from the abutment portion along the clamp bars towards the holder portion and which can be pulled towards the holder portion.
In accordance with a second aspect of the present invention, there is provided an apparatus for inserting a laryngeal mask comprising: a pair of clamp bars which are arranged to hold therebetween a tube connecting portion provided on an outside surface of the laryngeal mask; pivoting means for pivotally supporting the clamp bars at approximately intermediate portions thereof such that front ends and rear ends of the clamp bars can respectively move towards and away from each other; and an abutment portion which is formed at the front ends of the clamp bars so as to abut a front end of the outside surface of the laryngeal mask.
When the apparatus according to the first aspect of the present invention is used, the tube connecting portion is first pushed into a space between the clamp bars in a condition in which the band piece is placed in abutment or contact with the outside surface of the tube connecting portion. The abutment portion which is formed by the connected portion at the front ends of the clamp bars is made to abut or to be held against the front end of the outside surface of the laryngeal mask. Then, by holding the holder portion with hand, the laryngeal mask is inserted into the larynx while pinchingly holding between the clamp bars the laryngeal mask at its tube connecting portion. At this time, the abutment portion serves to prevent the front end of the laryngeal mask from peeling or bending towards the outside, thereby ensuring a smooth insertion of the laryngeal mask into the larynx. After the above-described insertion, the band piece is pulled out. According to this operation, the tube connecting portion is forced out from the space between the clamp bars, and the clamp bars can be pulled out or withdrawn while leaving the mask inside the larynx.
When the apparatus according to the second aspect of the invention is used, the pair of clamp bars are closed or moved towards each other while the abutment portion at the front end of each of the clamp bars is brought into abutment or contact with the front end of the outside surface of the laryngeal mask. The laryngeal mask is held at its tube connecting portion in a pinching manner between the clamp bars and is inserted into the larynx in this condition. Thereafter, the clamp bars are opened or moved away from each other and are pulled out while leaving the mask inside the larynx.
Whichever of the above-described apparatuses for inserting the laryngeal mask may be used, the mask body at the front end of the laryngeal mask can be held by the apparatus for inserting the laryngeal mask. Therefore, it becomes possible to control the position of insertion of the mask body at a free will of the operator and, as a result, the ratio of occurrence of abnormally positioning the laryngeal mask can be decreased to a minimum.
Furthermore, since it is not necessary to insert the operator's fingers into the oral cavity of the patient, the chances of infection through contact between the operator and the patient can be decreased. The problem of allergy through the use of rubber gloves can also be solved.
The use of the above-described apparatuses for inserting the laryngeal mask makes it possible to insert the laryngeal mask without bending the head of the patient backwards. The apparatuses can therefore be used to advantage to maintain an airway in case of head injury where the patient's head is difficult of urging backwards.
If the above-described apparatuses for inserting the laryngeal mask are used, it becomes possible even for an unskilled operator to easily insert the laryngeal mask and, furthermore, it becomes possible to insert the laryngeal mask without exerting undue force to it. The frequency in which the mask can be repeatedly used increases and it is therefore very economical.